Sandwich plate stepped risers

Abstract

A two-tired seating riser for a sports stadium comprises upper and lower metal plates bonded together by a solid elastomer core. The elastomer core has different thicknesses in the treads and rises. The lower tread has a lip portion in which the metal plates are flared to facilitate alignment with the riser below.

1. A stepped riser comprising:
 one or more generally horizontal treads; and 
 one or more generally vertical rises, each of said treads and rises comprising a sandwich structure having upper and lower metal plates and an intermediate layer of a compact polyurethane material bonded to said metal plates so as to transfer shear forces therebetween, 
 wherein each of said treads extends between adjacent rises and comprises said sandwich structure throughout its extent between said adjacent rises, and 
 wherein each of said rises extends between adjacent treads and comprises said sandwich structure throughout its extent between said adjacent treads. 
 
   
   
     2. A stepped riser according to  claim 1  wherein said riser is a seating riser. 
   
   
     3. A stepped riser according to  claim 2  further comprising mounting details for at least one seat and/or railings. 
   
   
     4. A stepped riser according to any one of  claims 1  to  3  wherein said riser has a maximum length of from 6 to 20 m. 
   
   
     5. A stepped riser according to any one of  claims 1  to  3  wherein said stepped riser has a run of from 600 to 1200 mm. 
   
   
     6. A stepped riser according to any one of  claims 1  to  3  wherein said upper and lower metal plates are formed by folding or roll-forming respective flat plates. 
   
   
     7. A stepped riser according to any one of  claims 1  to  3  wherein said intermediate layer is thicker in treads of said stepped riser than in rises. 
   
   
     8. A stepped riser according to  claim 1  wherein one of said rises joins the front edge of an upper one of said treads to the rear edge of a lower one of said treads and a said second rise extends upwardly from the rear edge of said upper tread, the front edge of said lower tread having a downwardly projection lip portion. 
   
   
     9. A stepped riser according to  claim 8  wherein said upper and lower plates are flared in said lip portion to receive an upper edge of an upper rise of a like stepped riser. 
   
   
     10. A stepped riser according to any one of  claims 1  to  3  wherein said upper plate is made of a different metal or alloy than said lower plate. 
   
   
     11. A stepped riser according to  claim 10  wherein said upper plate is more corrosion resistant than said lower plate. 
   
   
     12. A stepped riser according to any one of  claims 1  to  3  wherein said upper plate is thinner than said lower plate. 
   
   
     13. A stepped riser according to any one of  claims 1  to  3  wherein said upper plate is provided with a corrosion prevention treatment. 
   
   
     14. A stepped riser according to any one of  claims 1  to  3  wherein said upper plate has a thickness in the range of from 2 to 10 mm, said lower plate has a thickness in the range of from 2 to 10 mm and said intermediate layer has a thickness in the range of from 10 to 100 mm. 
   
   
     15. A spectator stand having at least one stepped riser according to any one of  claims 1  to  3 .